This song was written about a heroin-addicted couple living in Dublin's Ballymun flats; the towers have since become associated with the song. Though a lot of time was dedicated to the lyrics, the music was improvised with co-producer Daniel Lanois during a recording session for the album. "Seven Towers" is the flats they lived in. "Sweet the Sin Bitter the taste in my mouth" refers to taking heroin/crack. The strongest reference to drugs is " you no i took the posion from the posion stream then I floated out of here) . The Song tittle is perfect meaning for the distillation of the dynamic of feeding on addiction. "She will suffer the needle chill no more " means she has od'd - Powerful song cried when first heard it. U2 are fantastic for writting songs that mean something whether its political, religous the Song is all about the Herion epedemic in Irland.